Re: [Gen-art] Gen-art] Review: draft-ietf-pce-pcep-domain-sequence

[Dhruv Dhody <[e-mail]>]

Hi All, 

Sorry for delay in replying, let me try to send you proposed text tomorrow as per Julien's suggestion! 

Regards,
Dhruv 

> -----Original Message-----
> From: Julien Meuric [mailto:[e-mail]]
> Sent: 31 October 2015 00:35
> To: Joel Halpern Direct; Dhruv Dhody
> Cc: A. Jean Mahoney; General Area Review Team; draft-ietf-pce-pcep-
> [e-mail]; Dhruv Dhody
> Subject: Re: Gen-art] Review: draft-ietf-pce-pcep-domain-sequence
> 
> Hi Joel, hi Dhruv,
> 
> Focusing on the Area ID issue, I'd support adding some text along with
> Dhruv's proposal, but stricter (not just deferring to "implementation's
> feeling"). I.e., Area IDs are AS-specific and mustn't cross AS borders;
> AS-local Area IDs may be used inside an AS (without restricting to the
> origin AS).
> 
> See you in Yokohama,
> 
> Julien
> 
> 
> Oct. 30, 2015 - [e-mail]:
> >>          Given that Exclude Route Objects are not interleaved with
> >>     include Objects, is there a restriction that Area IDs may only
> be
> >>     excluded from paths within a single AS?
> >>
> >>
> >> [Dhruv]: I guess this would depend on the PCE behavior during
> >> inter-AS path computation i.e. PCEmay feel the area id subobjectis
> >> irreleventand strips from the XRO before sending the request to
> >> another PCE ​ or it might keep it intact. 
> >>
> >>
> >> This would be in s
> >> ​pi​
> >> ritof RFC 4874 where
> >> ​-
> >>
> >>
> >> ​
> >> The number of subobjects to be avoided, specified in the
> >>     signaled XRO, may be constant throughout the whole path setup,
> or the
> >>     subobjects to be avoided may be removed from the XRO as they
> become
> >>     irrelevant in the subsequent hops of the path setup.
> >>
> >> We can always
> >> ​use 
> >> EXRS in IRO specify the intentions much more clearly.
> >>
> >> If you agree, we can work on some text to add.
> >
> > I still can not see how the Excluded Route Object with an Area ID
> will
> > work.  How will a PCE which receives such a request know what AS it
> > applies to?  It works fine if the whole path is within one AS.  But
> if
> > this is a multi-AS request, the AS elements, if present at all, are
> in
> > the IRO.
> > The most obvious approach would be to declare that the PCE shall
> > assume that all Area ID exclusions apply to the origin AS.